DESCRIPTION (Adapted from Applicant's Description): The objective of this proposal is to understand molecular mechanisms involved in the regulation of transcription in early vertebrate development. Normal development results from an exceedingly complex hierarchy of regulatory interactions -- many at the transcriptional level. The amphibian, Xenopus laevis is an ideal experimental organism for this study as it offers both an excellent, well- established biochemical system and thoroughly characterized, external development. The candidate s long term career goals are to establish an independent research group and to study developmental regulation of gene expression at the molecular level. Of particular interest are regulatory mechanisms imposed by chromatin -- with a special emphasis on post- translational modifications of the core histones. Recent experiments have underscored and highlighted tested observations demonstrating a direct and potentially causal relationship between active transcription and histone modification.